u-boot/arch/arm/cpu/arm926ejs/mx28/mx28.c
Marek Vasut 22fe68fbdc iMX28: Fix ARM vector handling
This patch introduces proper ARM vector handling for i.MX28 CPU. This issue
wasn't addressed because the interrupts weren't enabled on any ARMv5 core,
therefore the issue wasn't noticed earlier.

In previous implementation, the vectoring code used by i.MX28 CPU when an
exception happened was that of the SPL. With this change, the branch target when
an exception happens can be reconfigured by U-Boot.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
2011-11-11 11:36:58 +01:00

221 lines
5 KiB
C

/*
* Freescale i.MX28 common code
*
* Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
* on behalf of DENX Software Engineering GmbH
*
* Based on code from LTIB:
* Copyright (C) 2010 Freescale Semiconductor, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/gpio.h>
#include <asm/arch/iomux.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/sys_proto.h>
DECLARE_GLOBAL_DATA_PTR;
/* 1 second delay should be plenty of time for block reset. */
#define RESET_MAX_TIMEOUT 1000000
#define MX28_BLOCK_SFTRST (1 << 31)
#define MX28_BLOCK_CLKGATE (1 << 30)
/* Lowlevel init isn't used on i.MX28, so just have a dummy here */
inline void lowlevel_init(void) {}
void reset_cpu(ulong ignored) __attribute__((noreturn));
void reset_cpu(ulong ignored)
{
struct mx28_rtc_regs *rtc_regs =
(struct mx28_rtc_regs *)MXS_RTC_BASE;
/* Wait 1 uS before doing the actual watchdog reset */
writel(1, &rtc_regs->hw_rtc_watchdog);
writel(RTC_CTRL_WATCHDOGEN, &rtc_regs->hw_rtc_ctrl_set);
/* Endless loop, reset will exit from here */
for (;;)
;
}
int mx28_wait_mask_set(struct mx28_register *reg, uint32_t mask, int timeout)
{
while (--timeout) {
if ((readl(&reg->reg) & mask) == mask)
break;
udelay(1);
}
return !timeout;
}
int mx28_wait_mask_clr(struct mx28_register *reg, uint32_t mask, int timeout)
{
while (--timeout) {
if ((readl(&reg->reg) & mask) == 0)
break;
udelay(1);
}
return !timeout;
}
int mx28_reset_block(struct mx28_register *reg)
{
/* Clear SFTRST */
writel(MX28_BLOCK_SFTRST, &reg->reg_clr);
if (mx28_wait_mask_clr(reg, MX28_BLOCK_SFTRST, RESET_MAX_TIMEOUT))
return 1;
/* Clear CLKGATE */
writel(MX28_BLOCK_CLKGATE, &reg->reg_clr);
/* Set SFTRST */
writel(MX28_BLOCK_SFTRST, &reg->reg_set);
/* Wait for CLKGATE being set */
if (mx28_wait_mask_set(reg, MX28_BLOCK_CLKGATE, RESET_MAX_TIMEOUT))
return 1;
/* Clear SFTRST */
writel(MX28_BLOCK_SFTRST, &reg->reg_clr);
if (mx28_wait_mask_clr(reg, MX28_BLOCK_SFTRST, RESET_MAX_TIMEOUT))
return 1;
/* Clear CLKGATE */
writel(MX28_BLOCK_CLKGATE, &reg->reg_clr);
if (mx28_wait_mask_clr(reg, MX28_BLOCK_CLKGATE, RESET_MAX_TIMEOUT))
return 1;
return 0;
}
void mx28_fixup_vt(uint32_t start_addr)
{
uint32_t *vt = (uint32_t *)0x20;
int i;
for (i = 0; i < 8; i++)
vt[i] = start_addr + (4 * i);
}
#ifdef CONFIG_ARCH_MISC_INIT
int arch_misc_init(void)
{
mx28_fixup_vt(gd->relocaddr);
return 0;
}
#endif
#ifdef CONFIG_ARCH_CPU_INIT
int arch_cpu_init(void)
{
struct mx28_clkctrl_regs *clkctrl_regs =
(struct mx28_clkctrl_regs *)MXS_CLKCTRL_BASE;
extern uint32_t _start;
mx28_fixup_vt((uint32_t)&_start);
/*
* Enable NAND clock
*/
/* Clear bypass bit */
writel(CLKCTRL_CLKSEQ_BYPASS_GPMI,
&clkctrl_regs->hw_clkctrl_clkseq_set);
/* Set GPMI clock to ref_gpmi / 12 */
clrsetbits_le32(&clkctrl_regs->hw_clkctrl_gpmi,
CLKCTRL_GPMI_CLKGATE | CLKCTRL_GPMI_DIV_MASK, 1);
udelay(1000);
/*
* Configure GPIO unit
*/
mxs_gpio_init();
return 0;
}
#endif
#if defined(CONFIG_DISPLAY_CPUINFO)
int print_cpuinfo(void)
{
printf("Freescale i.MX28 family\n");
return 0;
}
#endif
int do_mx28_showclocks(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
{
printf("CPU: %3d MHz\n", mxc_get_clock(MXC_ARM_CLK) / 1000000);
printf("BUS: %3d MHz\n", mxc_get_clock(MXC_AHB_CLK) / 1000000);
printf("EMI: %3d MHz\n", mxc_get_clock(MXC_EMI_CLK));
printf("GPMI: %3d MHz\n", mxc_get_clock(MXC_GPMI_CLK) / 1000000);
return 0;
}
/*
* Initializes on-chip ethernet controllers.
*/
#ifdef CONFIG_CMD_NET
int cpu_eth_init(bd_t *bis)
{
struct mx28_clkctrl_regs *clkctrl_regs =
(struct mx28_clkctrl_regs *)MXS_CLKCTRL_BASE;
/* Turn on ENET clocks */
clrbits_le32(&clkctrl_regs->hw_clkctrl_enet,
CLKCTRL_ENET_SLEEP | CLKCTRL_ENET_DISABLE);
/* Set up ENET PLL for 50 MHz */
/* Power on ENET PLL */
writel(CLKCTRL_PLL2CTRL0_POWER,
&clkctrl_regs->hw_clkctrl_pll2ctrl0_set);
udelay(10);
/* Gate on ENET PLL */
writel(CLKCTRL_PLL2CTRL0_CLKGATE,
&clkctrl_regs->hw_clkctrl_pll2ctrl0_clr);
/* Enable pad output */
setbits_le32(&clkctrl_regs->hw_clkctrl_enet, CLKCTRL_ENET_CLK_OUT_EN);
return 0;
}
#endif
U_BOOT_CMD(
clocks, CONFIG_SYS_MAXARGS, 1, do_mx28_showclocks,
"display clocks",
""
);